Various elements, such as the motive of consumers, advertising media, shops, manufacturers, experts (critics), etc. are involved with one another in human daily consumption activities. In this document, these factors concerned with consumption activities are referred to as “subjects.” These subjects have various relations with one another. It is assumed there is some kind of trust relation among these subjects. Consumers can obtain various information indicating the relations among these subjects. A commercial article A is made by a manufacturer B, and sold at a shop C. In a mode of the prior art, manufacturer B advertises the commercial article A by using the Internet, and shop C advertises the commercial article A by utilizing inserts in local newspapers.
Furthermore, a critic D analyzes commercial article A and places the analysis in magazine E. The same consumption activities are carried out on other goods, and considerable information about the article, manufacturer, shop, expert and the magazine is available. Consumers frequently cannot judge which manufacturer, shop, expert or the like can be trusted. In order to solve the above problem, the prior art has provided an indicator or information about credibility of manufacturers, shops, experts, etc.
It is more advantageous to obtain information about the trust values relevant to “subjects” in the consumption activities, and information about personal taste of the above information. It is known to use individual personal taste information about the to obtain the most credible information about consumption activities.
Prior art disclosing the foregoing include:
(1) Laid-open JP Patent Publication (P1999-306185)
(2) Lawrence Page; Sergey Brin; Rajeev Motwani; Terry Winograd. The PageRank Citation Ranking: Bringing Order to the Web. Technical Report. Stanford University, 1998.
(3) Noriko Arai; Kazuhiro Kitagawa. Personalization technique. Nikkei Electronics, 2003-02-03.
In JP P-1999-306185, PageRank is expanded so that texts and multimedia data and information of persons accessing these data are installed in a link structure as virtual web pages. In addition the web pages have ranking of information. When a user accesses various multimedia data on the Internet to download the data or register the data as bookmarks, the link structure of the web pages is expanded and the degree of importance is calculated. In the PageRank method disclosed in the Page et al document, web pages on the Internet are defined as nodes, and the trust values thereof and the estimating method thereof are described. However, the PageRank method targets only the importance degree of the web pages on the Internet. Accordingly, there is no reflection of information concerning subjects which are not described on the Internet. Thus the Page Rank method does not always provide consumers with the best information.
The Arai document introduces a personalization technique relying on user likes and dislikes. According to this technique, goods are recommended or introduced on the basis of the taste information of individuals. Arai et al includes a profile matching system, a rule base system, and a collaborative filtering system. According to these systems, goods which seem to be best for individuals are recommended on the basis of information such as individuals' taste information, purchase records, purchase patterns of general consumers, etc. However, in these methods, no consideration is paid to information about the trust values of subjects in consumption activities. Accordingly, an uncertain element as to whether it is truly good to purchase a recommended commercial article or the like may remain regarding the recommended commercial article or the like.